[Talk-transit] Summary of Public Transport Proposal Criticism -> a real example from Zürich

Dominik Mahrer (Teddy) teddy at teddy.ch
Thu Feb 10 10:01:47 GMT 2011


On 09.02.2011 23:12, Michał Borsuk wrote:
> On 02/02/2011 03:14 PM, Dominik Mahrer (Teddy) wrote:
>> On 02.02.2011 13:04, Michał Borsuk wrote:
>>> Let's just get down to differences, I say your proposal is too
>>> difficult. I've already spoken well about its data integrity, but new
>>> users don't care about it. We need something that is as good as yours in
>>> data integrity, and as easy to grasp as my proposals.
>>
>> Yours is good for beginners. And yours is also good for a white area
>> mapper.
>>
>> Advanced mappers are not happy with it.
>
> Enter scalability. Those two proposals mixed and *ordered* in a sensible
> manner can provide ease of use, as well as sufficient coverage of more
> advanced issues. For beginners level 1, for advanced users with big
> needs level three.
>
> In other words, with very little cutting we'd simply need to order
> jobs/tasks for mappers from easy to advanced, write a wiki page, and
> there you go.
>
> This sorting-and-ordering would be a major task, so it needs to be done
> in a quiet atmosphere.

Basically I call your request "good", but I'm not sure about the levels. 
For a bus stop, what would be level 1 for you, what level 2 and 3?

If I visit a bus stop by foot I can manage to map the pole/platform. So 
this could be level 1. But when I visit within the bus, I can only 
manage to map the stop position. So this would be level 1. What should 
be level 1 then?

>> I tried to reduce my proposal to allow simpler cases. stop_area_group
>> has been completely removed. A lot is now optional (stop_position,
>> platform, stop_area, route_master). So it should be possible for
>> beginners to learn step-by-step what they want/need.
>
> Genau.
>
> Unfortunately, bad documentation seems to be a standard among FSF
> projects. I see few volunteers to do that work.

Perhaps I misunderstood something. I wrote a proposal that should cover 
all what is technically needed to map on an advanced level and also 
permits beginner level mapping. But I did not write a beginners howto or 
a public transport tutorial. I thought such a tutorial would be based on 
an approved proposal.

Based on the point of view that you see the proposal as a tutorial, I 
understand now many (if not all) of your criticism! If you see my 
proposal as a tutorial, it is bad. Very bad.

As I have written I do not see my proposal as tutorial, I see it as 
description of the technically needed that fulfills data integrity. The 
tutorial is the next step after the proposal is approved.

>> And one relation per direction is easier to explain then
>> forward/backward roles.
>
> Yes, but it has a steeper curve if one relation per direction is
> obligatory.
>
> Still, what about variations (like a,b,c,d, but under one line?)

I do not want and I can not forbid using one relation for both 
directions. One relation per service is IMHO better then none. And one 
relation per direction is better then one per service. In the tutorial I 
would explain this. If anyone thinks one relation is sufficient then 
he/she should only use one relation. I know services in Switzerland 
where this is the case and I by myself would not create two 
direction-relations (especially single track, rail-bounded and 
bidirectional vehicles that has its platform on only one side). But if a 
tram line has mapped every track separate instead of only one way or a 
bus line that has plenty of one way streets, it would make sense to also 
create two relations for the two directions.

>> And I do not think we (mappers) can replace an existing public transport
>> routing solution like hafas (too complex and too dynamic).
>
> There have been calls for this. IMO it is feasible, but as a layer on
> OSM, not within.

Maybe, you are right. But then the next question that pops up is: Do we 
then need the bus routes within OSM at all? Wouldn't it make more sense 
to move them to this new layer?

> By the way, what do you mean "dynamic"? I don't have a very good opinion
> of HAFAS, it does its job, but is very old, and IMHO at its edge of
> development due to silly data structures.

With too dynamic I mean that the timetables can change every year.

>> The maximum
>> possible in my opinion is to import this data into OSM.
>
> That has been done.

Partially, yes.

>> But with a single route relation solution I do not see such a solution.
>
> Neither with one route per relation, but I've already covered the topic,
> exactly in this thread. You name a line in ZVV area, I provide you (if
> time permits) with routes and bus stops under that line.
>
> In other words, automatic import of HAFAS route data to OSM is not
> possible, because under each line sits a collection of routes, minimum 4
> (unless the terminus is also the depot). Those less used must be removed
> from the import.

Yes, of course, if you import the whole data from Hafas you end up with 
a huge number of relations. But if you import and maintain it 
automatically, do we have to care about the number of relations?

If we map it by hand, we can reduce it to what makes sense. For example 
leave away all the relations that end earlier.

Teddych



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